WTF - My car is a turd....

[Ricersux]

ok, so I get into boost and up till about 50 percent throttle everything is fine. Floor it and it falls on its ass and sputters like a mutha. Anything above 10psi and it just won't go...keep your foot out of it and it runs pretty damn good...any ideas?


2G AWD
EVO 16G

 

[1fast97gsx]

did it just randomly start doing this or was that after installing something? It's most likely fuel cut or boost leak.

 

[Ricersux]

Fuel cut...not sure...about that. I can't find any leaks either...how would I go about finding a boost leak???

It just started...first the thing was overboosting on the HKS EVC, so we disconnected it, hooked everything back up to stock and it falls on its ass.

 

[92redman]

I can't find any leaks either...how would I go about finding a boost leak???

http://www.dsmtuners.com/forums/search.php?searchid=385619

 

[92redman]

besides the number of mechanical possibilities, there are almost endless electrical possibilities. I would suggest trying to find other threads about hesitation, bucking, poor performance and start narrowing it down.

Have you even done a tune up recently?

 

[pimpinboudy]

i had the same problem with my car and it was my MAF it was broken and i replaced it all was better
james

 

[dnelsontsiawd]

I would check your caps on the ecu
Let us know what fixed it please!

 

[phatTSi]

Are you sure you hooked up the stock bcs correctly, if you put the vacuum lines on backwards it will boost but sometimes it will hesitate like your describing. Not sure if this is your problem but its an idea.

 

[meh]

plugs and wires....figure out your vacum hoses first, if you still have the problem, plugs and wires.

 

[Ricersux]

Can someone point towards a link for "How to check for boost leaks?" or something...I did a quick search but didn't see anything. I need to know if someone also might have a better / bigger vacuum diagram for me to see if I have something backwards. I appreciate the help guys....DSM'er Rock!!

 

[ArticNemesis]

http://www.vfaq.com/mods/ICtester.html


and quit crossposting the same problem in multiple forums.

 

[Ricersux]

Ok I check for boost leaks...found a couple...one was the J pipe coupling the other leak seems to be coming from the Intake Manifold...almost like it is a blown gasket or something. Also, at what point should I hit fuel cut? That is kinda how it feels too...we fixed the obvious leak went and test drove it and it is much better but still not 100%...probably more like 75%. If I only go to part throttle she runs damn good but when I step on it the thing sputters and backfires act like shit. Any other suggestions???

 

[beat90tsi]

Mine just started doing the same shit....so annoying.
It was running like a hoss wed night, but I had a little knock, so I put my afpr on yesterdayand dropped the pressure a few psi below stock, then added some fuel. It totally breaks up after it spools, backfires and shit, awful. I keep logging it, I get no knock and everything appears fairly normal. I guess I'll try the plugs and wires and boost leaks tomorrow.

For the record I'm running the MAF-T, old version, 3.5" maf, 650s, wally 255 and fullthrottlespeed.com afpr on my 90 AWD.

What you described is exactly what I'm experiencing, part throttle it feels great, then it falls on it's face when I go WOT. It's a similar feeling to blowing off an IC pipe, but it continues to run normal below full boost.

I'm thinking of going back to my BPR8ES plugs, the 7s are ok, but I had no problems on the 8s. What is a good gap for running ~20psi?

 

[sweet97]

I was going to ask why you were runnng the NGK 8's and then saw that you must have the 14B. 650's and a W255. You're working it! 20PSI and stock IC too! Do you have a logger? You must but i missed it. I'll be back, gotta look! Yeah logger. I'm fairly new to DSM's andhave 5 months to learn so please beat90tsi post the cure when you find it. Mark

 

[beat90tsi]

I have a 16g, I'm running 7s now, I may switch back to the 8s. I have a logger. I have a supra IC. Any ideas on how to fix my problem?

 

[91_laser]

have you checked your plugs and wires yet?

 

[beat90tsi]

wires aren' too old, but they aren't upgraded either,
I will have to try them, I'm stuck here at work until 11.

the really strange part is that at part throttle(part boost) it feels great, but at WOT it blows ass

anybody around with a 90 ECU that wants to swap me?

 

[mooditude2]

Try checking your alternator to see if its good or not. My buddy had the same problem with his WRX and thats what it turned out to be.

 

[sweet97]

Beat90tsi do you buy your gas at the same place? Possibly bad? Have you checked the MAF-T settings? I have tinkered with my settings and had them messed up. mark

 

[beat90tsi]

i just filled up with sunoco 93 today, but obviously i can't rule out bad gas....
i was dicking with the maft all day today, once with it zero'd out it ran pretty good, then it hit fuel cut, but w/650s i certainly shouldn't be zero'd out, i can watch the low fuel trim drop when it's that low, i need be at least at the 550 setting, if not leaner

my alt is putting down 14.2 at idle, i haven't actually checked in the logs to see if it's dipping lower at speed, but i doubt it....now that i think about it, i looked at my peak/min values and it was never below 13.xx, so the alt isn't the issue, i tend to glance at the voltages because i had an alt crap out before

i fear the ecu may be taking a dump on me

it's basically like it takes a dump in open loop, it runs fine in closed loop

 

[ArticNemesis]

Just curious why you chose to use a plug 2 ranges colder than stock.?

I'm still betting boost leak. Check the manifold gasket and replace if needed, check your fuel injector o-ring gaskets also, it can leak from there. Check both throttle body gaskets (they are usually the leak 75% of the time). Make sure ALL of your vaccuum hoses are connected or blocked off at some point.

Because of the fact that it doesn't do it till you try and push full boost, I going to say it's a gasket somewhere. It is weak, but will hold until you try to force full pressure on it.

[edit] you mentioned the leak around the manifold, and havent' said you've fixed it so far.. Find it and fix it. So you are only dealing with one problem and not a combination of problems.

 

[AL92]

There are lots of things that can contribute to this.My new 50 trim was a pooch after just installed it.Some things that seem to have fixed it ..well had pinched almost shut intercooler lower pipe.I had blown gasket between turbo and exh man.I had and this could be reason a lot of our cars run bad is a dying alt .sometimes it would work half assed and sometimes not.Lately it got real bad and betting our ecus,injectors and ignition all need a good voltage to work right.My car is way better with the new alt.Also went to new battery.
And recently put in new upgrade maft chip.The new chips seems better than the old one.
Also on my maft had the high rpm problems when had wot turned up too high.Also not sure like colder plugs or if they are necessary if you only go momentarily into high boost.Maybe with back to back drag runs but on the street not sure where you guys live but in my city can't even stay at 10psi with my 50 trim for more than a few seconds.Run out of road or have traffic in way or worry about car being inpounded and going to jail.

Of course basics..check plug gaps and wires.Also can't hurt to change fuel filter.And would test things like coil pack etc.t

 

[beat90tsi]

fuel pump and filter are both brand new...
my fuel pressure was too low, i guess setting the base with the vac line off isn't always right....I dunno, but that was it, it runs like a hoss now 20psi to redline pulls like a mother, i'm going to the track today

thanks for your suggestions, I was dumb and it was really simple

maybe i'll post my timeslip in this thread tonight

 

[Maglin]

Well glad you got it fixed. If you change something and all of a sudden it doesn't run right chances are high it's what you changed that made the problem. When you change a ton of things at the same time is when you have a hard time tracking down the culprit.